Artemis - A strong name. Usable, but it would need a softer middle to balance it outCassandra - Very pretty!Cleo - Not a personal fan, but it's not a bad choiceElizabeth - Great classic name. Only concern would be popularityMiriam - To me, it's a little dated but the nn Mimi would be so cute for when she's youngNina - I like it! Ages well and has some spunkPersephone - Reminds me of Stephanie, but betterMatthias - Love it! Very handsome and freshPerseus - It might be a little much as a first, but nn Percy is greatThaddeus - Lovely-sounding name. Would also work well as a strong middle
Sibling for Miriam - I think Thaddeus and Persephone work best with it

@bee49- with Elizabeth, popularity is my concern. The supposed dated-ness of Miriam is my concern too, but I think among the Jaylas and Kaitlyns, Miriam would be fresh. Thanks for all the positive comments!
@silvercandles-I actually know tons of Athena's (I'm Greek) and it sounds really weird in Greek (it is pronounced more like ah-THEEN-nah); but I haven't met any Artemises. I pronounce Nina Neen-uh, but Nine-uh is cool too. Thanks for all help!

Artemis - Hate Missy (long story) but I love the name by itself. Have met Athenas bbut no Artemis. A strong, beautiful choice!Cassandra - This name has been going back and forth from my list. Love the nn Cassia with it, but there are so many that she'd be able to choose from if she wanted when she was olderCleo - Nms, and doesn't exactly fit with your othersElizabeth nn Libby - Haven't seen this in the fn spot for a while. Maybe too long? It is popular, but nn Libby or Lilibeth are less commonMiriam - One of my grandmothers names (in case you were curious, sibset was Libby, Ruth, Miriam, and Etta/Yetta). I think it'd be fresh with some of the names used today. If you're not sure can I suggest Moirah or Mariska.Nina - I watch too much Project Runway because all I can think of is NinaGarcia making fun of my clothesPersephone - I like it for the same reason as Cassandra